DESCRIPTION: (Applicant's Abstract) Current treatment modalities for optic nerve related blindness focus on topical drug application to lower intra-ocular pressure, systemic anti-inflammatory/immune suppression with steroids, or surgical decompression of the nerve sheath. The long-term goal of this research is to create a novel treatment approach for optic nerve axonal disease. The project objectives are to design, construct and test an orbital endoscope for visualization and treatment of optic nerve diseases. Clinical applications of the proposed orbital endoscope include implantation of a slow release drug delivery mechanism for direct and sustained treatment of glaucoma or orbital tumors such as meningiomas, local application of immunosuppressive or neuroprotective agents in diseases such as optic neuritis or traumatic optic neuropathy and laser application to open the nerve sheath in pseudotumor cerebri. Specific project aims include developing an endoscope capable of safely reaching the posterior orbit, developing delivery ports, and demonstrating the safety in an animal model. The design will include an endoscopic image fiber bundle, illuminator bundle, and a delivery channel. This design driven development of an orbital endoscope will have a high impact on many of the blinding diseases which are currently poorly treated. The resultant capability to directly treat optic nerve disease will be a major advance for Ophthalmology. Collaboration on this unprecedented approach includes the expertise of an orbital surgeon/neuroophthalmologist, glaucoma specialist and optical engineer.